In FIGS. 7(a) and 7(b), a fusible link unit 1 (fuse unit 6 of Japan Patent Publication No. 2001-297683; hereinafter “JP '683”) is connected to a battery of an automobile and supplies electric power to loads. The fusible link unit 1 includes a conductive busbar 3 (fuse element 1 of JP '683) which has a plurality of fusible parts 2a, 2b to 2e (fusible parts 2 of JP '683), resin housings 4 and 5 (resin bodies 4 and 5 of JP '683) which are integrally formed at predetermined positions of the busbar 3, and transparent resin covers 6 and 7 (covers 26 and 36 of JP '683) which are fastened to the resin housings 4 and 5.
The busbar 3 has a battery terminal connecting portion 8 (power source connecting parts 19 and 32 of JP '683) which is connected to a battery terminal not shown in the figure, and a wire connecting portion 10 (terminal connecting parts 31 and 34 of JP '683) which is provided with a bolt 9 (stud bolt 34 of JP '683) and can be connected to the terminal of an electric wire which is not shown in the figure, and the fusible part 2a, all of which are portions that are exposed from the resin housing 4. Further, the busbar 3 has the fusible parts 2b to 2e, and a plurality of tab terminals 11 which are connected to the loads, both of which are portions that are exposed from the resin housing 5. The busbar 3 has a hinge shown with a reference sign 12 which is another exposed portion. The hinge 12 is formed as a portion where the resin housings 4 and 5 are bent with respect to each other.
The resin housings 4 and 5 have exposure windows 13 and 14 (empty chambers 24 and 35 of JP '683) in order to expose the fusible parts 2a-2e. The exposure window 13 is formed so that the fusible part 2a can be observed from both directions, or from the front and the back of the resin housing 4, and the exposure window 14 is formed so that the fusible parts 2b to 2e can be observed from both directions, or from the front and the back of the resin housing 5. The exposure windows 13 and 14 are covered with transparent resin covers 6 and 7 from both directions, or from the front and the back of the resin housings 4 and 5. The exposure windows 13 and 14 and the transparent resin covers 6 and 7 are fastened by lock projections and lock parts which are hooked to the lock projections.